Violence and severe mental disorders

People with psychosis are at risk of several detrimental outcomes, including a small but increased risk of committing violence.

This project seeks to improve our knowledge of psychotic violence by investigating the influences of social, psychological and biological factors with an integrative perspective.

About the project

Most persons with severe mental disorders will never commit a violent act. Still, the small but significant increase in violence risk stigmatizes a whole group of patients.

According to Norwegian penal law, offenders cannot be held legally responsible for actions committed in a state of psychosis.

In clinical practice, current and future violence risk are evaluated. Such evaluations are difficult and raises several concerns:

Why are people with psychosis at increased risk of committing violence1?

What characterizes psychotic violence?

How can we best predict violence among persons with severe mental disorders?

Background

Psychotic disorders, such as schizophrenia and bipolar disorder, affect about 3 % of the population worldwide.

Psychosis is a risk factor for committing1 and to be victimized by2 violence. Adverse environmental factors such as substance abuse, low socio-economic status, and childhood abuse or neglect increases risk for both violence and psychotic disorders3, 4.

The association between psychosis and violence remains after controlling for known environmental risk factors1, 3, indicating that the environment alone cannot explain the increased violence risk in psychosis.

Moreover, although psychosis symptoms such as delusions are associated with violence5, 6, the vast majority of persons with psychosis have never committed a violent act.

Violence and anti-social behaviour have been linked to alterations in specific brain circuits7, 8, and persons with psychosis show subtle brain abnormalities9-11, but such neurobiological differences are found on group level only, and cannot be used to explain the behaviour of individuals.

In order to better understand psychotic violence, the influences of social, psychological and biological factors must be taken into account. Only by combining the three areas of research can we gain a comprehensive understanding of psychotic violence, and counter reductionist explanations and stigmatizing beliefs.

Objectives for our research

Study the neurobiological, psychological, and social trajectories of violence among persons with severe mental disorders and develop a bio-psycho-social model for psychotic and non-psychotic violence that is clinically meaningful.

Study the stability of the neurobiology, symptom profiles, and influence of social factors on psychotic and non-psychotic violence over time.

Our long-term aim is to use this knowledge to give better treatment and improve diagnostic procedures and violence risk evaluations which can contribute to improve the legal rights of psychotic and non-psychotic offenders while ensuring the protection of society and reducing stigma.

Methods

We use advanced neuroimaging methods in combination with registry data and thorough clinical characterization of psychotic and non-psychotic perpetrators of serious violent crimes to investigate the biological characteristics, social trajectories, and psychological core features of psychotic violence.